The present application relates to an all solid-state thin film battery and a method of forming the same. More particularly, the present application relates to a method of forming an all solid-state thin film battery and a solid-state lithium-based battery having enhanced performance. The method can be used to fabricate micrometer scale sized batteries.
In recent years, there has been an increased demand for portable electronic devices such as, for example, computers, mobile phones, tracking systems, scanners, medical devices, smart watches, and fitness devices. One drawback with portable electronic devices is the need to include a power supply within the device itself. Furthermore, it is also useful to scale the battery device size down to the micron level to integrate the batteries into small scale devices such as, microprocessors, sensors, or IoT (internet of things) systems. Typically, a battery is used as the power supply of such portable electronic devices. Batteries must have sufficient capacity to power the portable electronic device for at least the length that the device is being used. Sufficient battery capacity can result in a power supply that is quite heavy and/or large compared to the rest of the portable electronic device. As such, smaller sized and lighter weight power supplies with sufficient energy storage are desired. Such power supplies can be implemented in smaller and lighter weight portable electronic devices.
Another drawback of conventional batteries is that some of the batteries contain potentially flammable and toxic materials that may leak and may be subject to governmental regulations. As such, it is desired to provide an electrical power supply that is safe, solid-state and rechargeable over many charge/discharge life cycles.
One type of an energy-storage device that is small and light weight, contains non-toxic materials and that can be recharged over many charge/discharge cycles is a solid-state, lithium-based thin-film battery. Lithium-based thin-film batteries are storage batteries that include two electrodes implementing lithium. Such lithium-based thin-film batteries are typically patterned utilizing photolithography and etching.
There is a need for providing a method of forming lithium-based thin-film batteries, and other types of all solid-state thin-film batteries, that avoids utilizing liquid-containing materials such as conventional liquid-based electrolytes to form the battery material stack. Moreover, there is a need for providing a method of forming a solid-state thin film battery that is compatible with existing CMOS (complementary metal oxide semiconductor) processes and which can be monolithically integrated to other microelectronic devices. Also, there is a need for providing a lithium-based thin-film battery that has improved device performance at fast charging speeds.